This invention generally relates to sealing the space between an adjacent nuclear reactor vessel annular flange and a surrounding ledge or plate to provide a water barrier for supporting a liquid in a cavity called a refueling pool. Seals for this purpose are known and are shown, for example, in U.S. Pat. No. 4,214,760 entitled "SEAL FOR ADJACENT PLATES" which issued to Dwaine A. Godfrey, July 29, 1980. Combustion Engineering, Inc., assignee of the instant invention, is the exclusive licensee under the above referenced patent.
The Godfrey type of seal is a temporary seal which is installed during nuclear reactor refueling outages but which is removed for normal reactor operation.
A southern Texas utility has permanently installed a refueling pool seal, although such a permanent installation is not normal. Moreover, it is not believed that others have provided in a permanent pool seal, significant nuclear shielding and insulation. Certainly, the instant structure is an efficient permanent insulated refueling pool seal and neutron shield which has not been known heretofore.